Suggest a new amp/preamp/Dac streaming combo

I think dedicated network players are going the way of the Dodo, just as dedicated wordprocessors once did (remember those?). After all, each time a new service is introduced, either the service provider or the player manufacturer will have to develop a new app, and that for many services and many players. The same was true for smart tv’s or disc players with streaming abilities. It is just not a viable business model, and as a user you are stuck in a dead end street.
The alternative is either using a pc of one kind or another, with its universal browser (the Raspberry Pi is very popular for this, but any laptop will be just fine), or streamers by market leaders like Google (Chromecast) or Apple (Airport Express). The beauty of these units is that they have such a massive market penetration that no streaming servce can afford not to develop an app for them, and you can connect them to your existing high end stereo system. Both the Chromecast and the Airport Express have good internal DACs that will not be out of place in pretty good systems, but if you want something better they also have digital outputs.
See here for a test of the Chromecast:
http://archimago.blogspot.nl/2016/02/measurements-google-chromecast-audio.html
http://archimago.blogspot.nl/2016/02/measurements-google-chromecast-audio_27.html
And here for one of the Airport Express:
http://www.kenrockwell.com/apple/airport-express-audio-quality-2014.htm
I prefer the Chromecast because once it is connected it no longer needs your smartphone, saving its battery. It can handle 24/96 files, and with BubbleUPnP it can also connect to a hard drive on a computer.
And the good news is that they cost next to nothing, so you can experiment without investing serious money.
Of course there are plenty of good modern amplifiers to choose from, also with inbuilt DACs. Even a cheap 2x100 watt Yamaha RN 803d receiver with digital inputs, Airplay and dlna is perfectly fine for anything other than inefficient speakers in large rooms. It even has a room eq system built in. There are now quite a few DACs with variable output (e.g. Pioneer U-05, Marantz HD DAC1, Benchmark DAC3, to name just a few that are more or less in your price bracket). Alternatively, and if you like playing audio and video discs, the Oppo UDP 205 4k disc player can also serve as a first rate pre amplifier with digital inputs for e.g. a Chromecast, and inbuilt high quaity DAC. Add a beefy power amplifier and you are done. The Benchmark AHB2 measures exceptionally well, with exceptionally low noise and distortion, but even a cheap 2x350 watt Yamaha P3500s pro audio amplifier is as good as many audiophile products: http://www.homecinema-fr.com/forum/amplificateurs-de-puissance-haute-fidelite/mesures-ampli-yamaha-p3500s-mise-a-jour-t30056383.html I recently bought the 2x250 watt P2500s for my son, and I cannot be happier.

However, many DACs now have a variable output (and some, like the Marantz and Benchmark units that I mentioned even have an analogue input). With these, all you need is a power amplifier. Personally, I don't use any analogue sources anymore now that the SQ of internet radio has come to equate or often surpass that of FM radio.

So the tuner is your only analogue source (you could use the digital output of the cd player). If you change to internet radio you will not need a single analogue input anymore, which greatly simplifies your choice. Comparing the sound quality of FM radio and internet radio is not easy because they each have their own specific weaknesses, but by and large I think most internet radio stations now have at least as good a SQ as FM radio, if not better. And the range you can choose from is virtually unlimited. We now use the TuneIn app for the Chromecast, and we could not be happier.

As for laptops: http://archimago.blogspot.nl/2013/04/measurements-laptop-audio-survey-apple.html
Their inbuilt DACs are mostly evil, but as a usb source they are fine. The biggest issue with desktop PCs is their fan noise, although here the new generation of small Intel Nuc computers in fanless cases can be a good option, as would be a Raspberry Pi if it is just for the music playing: http://archimago.blogspot.nl/2017/01/measurements-raspberry-pi-3-as-usb.html
For the OP, I think his best bet is to get a Chromecast Audio for a few dozen dollars, connect it to the analogue input of his current system, and experiment with streaming services to see if he likes this way of listening. If he does, and only then, it is time to think about the electronics. I would go for a DAC with multiple digital inputs and variable output (e.g. the Pioneer U-05 or the Benchmark DAC 3), using a Chromecast Audio and its digital output as a streamer (and also  the digital outputs of the television and the disc player). If video is important, an Oppo 205 will do the same job of DAC and preamplifier and will also play cd's. Plus a beefy solid state power amplifier.
With the Chromecast Audio there is one thing to consider if using the analogue output. You can choose between a Normal and a High Dynamic Range setting. You would think more dynamic range is always better, but the snag is that this is actually not a dynamic range setting, whatever the misleading title. The difference is just the output voltage, with HDR equal to the 2V Red Book Standard. If your rca line input is for 2V, choose this one, but many analogue inputs are more sensitive, in which case you get a cleaner less clipped sound with the lower output setting.
By the way, this sensitivity matching problem is also an issue with many cd players that should have the 2V output, but are often even hotter. If your amplifier has the traditional more sensitive inputs, you get clipping distortion, which contrary to what you may expect is quite common, and may in part explain the reticence about ’digital sound’. A telltale sign is if you do not have to turn up the volume very far to get a loud signal. The solution is simple: insert an inline attenuator or an attenuation cable.